Revert "Merge pull request #2101 from ahcorde/sudoku_ipythonNotebook"

This reverts commit 04e51f3f3c83a19b8760dceb1727ce7357f50472, reversing
changes made to 11c25d37eaa73a4b0a9210a6d70da4685cf3bc40.
Merge pull request #2108 from karlnapf/develop

Revert "Merge pull request #2101 from ahcorde/sudoku_ipythonNotebook"